Actually, the bottled boats are built outside, with laid down poles. Then, put in the bottle and with small tongs, rise then, making it look like a regular boat. Anyway, you can even build them inside with long and thin tools, since you have a lot of room to operate inside the bottle.
(My grandfather used to make some).

However, unless it is a trick :
- non-moving/functionning rubik's cube, inserted bricks after bricks, simply posed above each other for the visual effect
- only half a bottle (we don't see the back it after all)
- photoshop editing
- ???
I think there is no way it is a fully functionnal rubik's cube built in a bottle, since i see absolutely no room to operate inside...

Tweezers and stuff? you ******* underestimate them, also you can take the outside bits off, but the inside would be a lot harder. Are you ******* daffy? there's no way you can assemble a rubix cube inside a jar.

Very clever, and epic decoration. All one must do is simply remove the bricks, discard the center of the cube, and gently insert each cube in the correct pattern with a gentle dab of glue.

Since many rubics cubes are kind of rounded off for smoother turning, and use stickers, you want to find a good, old style one where the colors are actually painted on, and the blocks are.well..blocks.

Then, find a swag old square jar, some nice craft glue, and maybe even sneak a little color changing LED light inside where the center of the cube once was, and boggle the minds with an epic center piece.

For those concerned about the LED light running out of juice, simply put a small watch battery on the bottom of the jar cap, use a very thin clear plastic wire, and connect it to the LED light before completing the cube. Once sealed, the wire will not be visible due to the glass, and you can change the battery when needed.

No, the cube was solid, when it was put in. The bottom of the jar was carefully melted off and then fused back on. I worked in an electronics store before and we had cell phones in glass bottles at display. They were put in the same way.